Swimming Pool Plumbing: Rigid PVC vs. Flexible PVC, Which is Better?

Visit any online pool and spa forum and you'll find that a leak is one of the most frustrating experiences a pool owner can have. Finding, fixing, and not to mention paying for a leak will make anyone want to pull their hair out!

Needless to say, a pool builder needs to use the best installation methods and building materials available to prevent leaks along with all the nasty consequences that follow.

Today I want to turn our attention to the most fundamental component of a pool's plumbing: Polyvinyl Chloride tubing, or PVC pipe.

There are two primary types of PVC pipe used in residential inground pool construction today:

Rigid PVC pipe

Flexible PVC pipe

Let's compare these subterranean tubes to determine which you would rather have under your pool patio.

Is rigid or flexible PVC pipe better for inground pool plumbing?

You should use only rigid PVC pipe for the plumbing in your inground swimming pool. Even though it's more difficult to install, it's much stronger than flexible PVC pipe, which isn't rated for underground use at all. Flexible PVC is easy to crush or puncture, and bugs like termites can chew through it.

What's the difference between rigid PVC and flexible PVS for pool plumbing?

What rigid PVC and flexible PVC have in common:

Rigid PVC and flexible PVC pipes both have essentially the same chemical make-up.

Both are cut and glued using the same tools and solvents.

They are joined together using the same PVC fittings.

What makes rigid PVC and flexible PVC different:

Rigid pipe, just as its name implies, doesn't bend on its own. This means whenever a turn in the pipe is needed, the installer either has to cut the pipe and install a fitting or heat bend the pipe to get around the turn. Both take time and varying degrees of skill.

Flexible PVC is made with plasticizers that make it softer and highly flexible. When a turn in flexible PVC is needed the installer simply forms the pipe around the bend and keeps on rolling. This method of installation is much quicker and easier than using rigid PVC pipe.

So far, we can basically see that we have a choice between a pipe that is stronger and more difficult to install verses one that is weaker and easier to install.

All things being equal, I'm going with the one that's easier to install! But alas, things are never quite that simple, are they?

Here's the deal:

Flexible PVC pipe is much easier to install, but should never be used on an inground swimming pool...period!

Why not?

The short answer:

Bugs

Pressure

Let's talk about that.

First of all, several years ago I attended a seminar on inground pool plumbing. The instructor passed a small section of pipe around the room. When it finally came around to me, I was astonished! It was a piece of 2" flexible PVC pipe with dozens of tiny holes in it. My first thought was "What the heck?"

Then the instructor said one word: "Termites!"

Flexible PVC pipe is simply not suitable for underground use, but don't take my word for it.

Kuriyama of America, a large distributor of flexible PVC states:

"....Spa Hoses (flexible PVC pipe) can be damaged by rodents or insects, including termites. Spa Hose should not be used underground in areas infested by termites. Our warranty does not cover damages caused by them...This product warning shall be given to every purchaser of Spa Hose. (Rev. 7/98)"